June 2004 - Boost - lists.boost.org

RE: [boost] Re: regression test tools ported to vacpp
by Rozental, Gennadiy 07 Jun '04

07 Jun '04

> Gennadiy Rozental wrote: > > > "Toon Knapen" <toon.knapen(a)fft.be> wrote in message > > news:40BF16BA.8080009@fft.be... > > > >>The regression test tools are finally ported to vacpp version 6 and > >>the > > > > I just spend half an hour to clean my code after this port. I do > > understand that you just wanted to make it work on your > compiler. But > > lets in a future first discuss it here on a list before you commit > > this kind of modifications. > > > > There was a discussion about all these issues for about a > week now with > clearly marked in the header that it was about the test > library. Since > you only responded to the last of the series of mails, I thought you > were OK with the other modifications. Yes. I was Ok with basic_cstring modification. Not the rest. I was actually hoped you (somebody familiar with PP) find a fix to IBM VA issues with BOOST_PP. As it stands now I simply disable access control for this compiler, what is wrong. > Generally I always contact the developer personally before > commiting a > change. However, I already have tried to contact you privately but I > never got a reply. It could be. I had to abandon three of my accounts lately. One because I moved. One because it's no longer free. One because it became unusable due to spam. Use gennadiy <dot> rozental <at> thomson <dot> com. > Anyway, in the future I will again try to contact you before > committing > soth. > > May I also ask to elaborate on what you found not to be clean > about the > port and how and why you changed these changes. This might be > interesting information for future ports. You couldn't just manually unfold macro definition all over the code. It makes code look like a mess IMO. See, what I did in cvs. Regards, Gennadiy.

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Borland and BOOST_NO_FUNCTION_TEMPLATE_ORDERING
by Robert Ramey 07 Jun '04

07 Jun '04

Using Borland 5.5 I compile the following: #ifdef BOOST_NO_FUNCTION_TEMPLATE_ORDERING #error "NO function template ordering supported" #else #error "YES function template ordering supported" #endif And I get: Fatal F1003 c:\boost_1_31_0\libs\serialization\test\test_zmisc.cpp 4: Error directive: "YES function template ordering supported" Yet C:\boost_1_31_0\more\borland_cpp.html seems to suggest that I should get NO. What am I missing here? Robert Ramey

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RE: [boost] Re: input_iterator_facade (was: Re: [iterator facade] Why isdereference const?)
by Rozental, Gennadiy 07 Jun '04

07 Jun '04

> I guess we're back to your old disagreements about > flexibility. Flexibility is > fine, but it adds complexity, both for implementors and the user, so > flexibility should be added only when absolutely necessary. > The eof_iterator > is intented to be as simple as possible. > > - Volodya Actually after some consideration I incline to agree with you on most points. Look in cvs on how my version looks now. Gennadiy.

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[assign library post review again]
by Thorsten Ottosen 07 Jun '04

07 Jun '04

Dear all, a new zip file can be downloaded in the files section in the assignment folder: http://f3.grp.yahoofs.com/v1/4NHBQHrGLW_kAudslwozEsdMfU_iY8Ja3CZu5N40ZMlffd… or http://tinyurl.com/27ldw We still need to find a name. If nobody else besides Pavel and Tom has an opinion, I will go for Boost.Assignment with a majority vote of 2 to 1. br Thorsten

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Re:[boost] Serializer and when to stop
by Robert Ramey 06 Jun '04

06 Jun '04

Darren Cook wrote: > I'm using boost::serializer between two programs: the first creates the > data then serializes it, the second loads that data in and analyzes it. > When I had just 420 data samples it all worked fine: I create a > vector<Sample> in memory, serialized it and loaded it in the other side. > When I moved to 7000 data samples the first program, the creator, sucked > all the memory from the machine and then some. 7000 samples? That doesn't seem very large in today's environment. I can't see why creating an archive should consume any significant memory at all. Nothing significant is constructed. Perhaps is a bug somewhere. In any case, you do raise in interesting issue which would crop up if serialization were used in something like data logging. > So I moved to serializing each data sample as it was created. > To read it back in I changed my code from this: > std::ifstream input_file(fname,std::ios::binary); > boost::archive::binary_iarchive archive(input_file); > std::vector<Sample> samples; > archive>>samples; > input_file.close(); > Into this: > std::ifstream input_file(fname,std::ios::binary); > boost::archive::binary_iarchive archive(input_file); > std::vector<Sample> samples; > samples.reserve(8000); > while(!input_file.eof()){ > Sample s; > archive>>s; > samples.push_back(s); > } > input_file.close(); > But every time it fails with an assert [1]. This seems to be when it has > reached end of file. I cannot know in advance how many data samples I'll > write to disk, so it seems I have three options: > A: Make a special "zero" version of Sample to mark end of file > B: At end of program 1 write the number of samples to a special file, > and read that in before starting the above loop, so I know when to stop. > C: Alter the serializer class to throw exception instead of an assert; > I can then catch it and carry on. I think I changed the assert/exception to check before loading rather than after for the next version. This would permit your code above to work as you expect. I'll have to double check. > What is the best way? Is adding a terminator byte to boost::serializer an > option (i.e. so I don't have to make a terminator version of each data > structure I want to serialize). > Incidentally my above loop does a copy of each sample as it adds it to > the vector. Is the above code going to be common enough to make it worth > including into boost::serializer as a helper function, which could then > be optimized with in-place construction or something clever like that? > (And then it could handle the termination handling itself as well.) The default implementation of STL collections create a new element on the stack and copy into the collection. Its as clever as I can make it without getting tripped up in things like exception safety, objects without default constructors, etc. Robert Ramey

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Wave/flex_string and replace< InputIterator > bug
by Reece Dunn 05 Jun '04

05 Jun '04

Hi all, I am implementing test cases to validate the implementation of my fixed_string class and basic_string_impl (based on flex_string) and noticed a defect in the implementation of: template< typename InputIterator > inline string_type & replace( iterator i1, iterator i2, InputIterator j1, InputIterator j2 ); It handles the Integral case fine, but when the InputIterators are actually iterators, it asserts false, where the standard dictates it returns: replace( i1, i2, basic_string( j1, j2 )); or equivalent behaviour, e.g. in the implementation I'm using: replace( i1, i2, std::distance( j1, j2 ), char_type()); std::copy( j1, j2, i1 ); Is there any specific reason for this, or is it an implementation bug? Regards, Reece _________________________________________________________________ Want to block unwanted pop-ups? Download the free MSN Toolbar now! http://toolbar.msn.co.uk/

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Re: [Boost-announce] Formal Review Tribool
by Haim Cohen 05 Jun '04

05 Jun '04

Hi, I am happy to contribute my review for the tribool library. I am a software engineer developing EDA (Electronic Design Automation) software, so I think I can contribute my 2 cents to the review of tribool, as I think EDA tools will benefit from this library. I did not compile the library. I have made a quick reading of this library, but an in-depth study of this problem domain before. First of all, my first comment is about the library's name, as well as the class name. In logic circuit simulation, there are 4 values : 0, 1, x ( which is tribool referred to as undetermine ), and z ( represents high impedance - or disconnection, and sometime referred to as "tri state" ). So, I think users will find it quite confusing when they see the 'tri' in the library's name. Since the library implements a logic value which has some value that is unknown, I would suggest 'unknown bool' or 'x bool'. Now to the interface. I think that a macro which enables renaming of the x value should not be supplied. This will make people's code less standard. Same as we all know what 'true' and 'false' mean, we should adopt a unique name for 'unknown yet quite determined logic value'. I think the default 'undetermine' name is not a good name. My suggestions : logic_x, x_value, x_logic, unknwon_bool . I also think the default tribool constructor should create a tribool object which is 'undetermine'. (Not false, as in the documentation) Besides the above, I think the interface of the class is good and succinct. Some point for thought : Users might want arrays of tribools, with all the support of bitwise operations. Is this should be a part of tribool as well ? I do not know. Now I will refer to the implementation. In real-life problems, programs might make a heavy usage of the tribool class for simulations of logic circuits. A logic circuit (at least the combinatoric part) is a DAG where nodes are logic gates, and directed archs are wires. This graph might be the result of a synthesis process, where a high level language for hardware description (e.g Verilog) is compiled into this DAG. Note : This is a very general and simple description of the process. Life are much more difficult. So, outputs will be calculated by performing lexicographic order of the DAG, and calculating from inputs to outputs. I am telling this, to convince that performance is *very* important here. With a quick look at the implementation code, I think that calculating the value using branches (if else) will not result with good performance. Calculations with true/false values only is fast - CPU vendors dedicate special hardware for this, so calculation can be made in one machine cycle. Even bitwise calculation (up to some word width) is done in one machine cycle. Compilers are making use of this, and (hopefully) compiles boolean and bitwise operators to the appropriate instruction. Unfortunately, I did not see any CPU which supports built in true/false/X arithmetic. And even if there are such CPUs available, we will not be able to use it, since boost libraries should be portable. So, it is very tempting to think - how can we implement efficient true/false/X arithmetic using the existing boolean arithmetic ? One tempting idea is to represent true/false/X with some integers, and use bitwise arithmetic to get the right results. It seems there are no such integer values. I think I even managed to proof this. Since there is already a library implementing 4 values logic (0,1,x,z) - which is SystemC - I took a quick look on how they do it with their 4-states logic data type called sc_logic. They use an approach which I think should be also used in tribool. It seems that they maintain lookup tables for each operation: AND, OR, NOT, XOR (!=) and XNOR (==). As the internal representation of tribool is enumerated type, we can use the integer value of this enumerated type to access the lookup tables (primitive 2D fixed-size and fixed-values arrays) and get the result of the calculation. This will be much faster since most CPUs has a special addressing mode for accessing arrays. So, I suggest to change implementation to use class-static fixed array to perform calculations. I know that the spirit of Boost is portability and not performance, but since what is suggested here is actually very similar to a primitive data type which might be heavily used in applications, I think it is important to consider performance as well. I hope this review would be found useful. Haim -- _____________________________________________________ Haim Cohen Software Engineer haim.cohen(a)analog.com / haimcohen2002(a)hotmail.com Analog Devices Israel (972) - 9 - 9715 406

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Re:RE: [boost] serialization request
by Robert Ramey 05 Jun '04

05 Jun '04

Jeff Garland wrote: > > Robert Ramey wrote: > > > > >Russell Balest wrote > > > > > >>Does someone know where in the code I can implement this easily. > > >>I just want to ignore the comments. > > >> > > >easy to accommodate. Just create a use the following in your > > >serialize > > >functions: > > > > > >Template<class Archive> > > >Void serialize(Archive, my_class & t){ > > > std::string comment; > > > ar & BOOST_NVP("comment", comment); > > > ar & BOOST_NVP("myclass_data", t);; > > >} > > > > > >In which case your XML output will look like: > > > > > >... > > ><comment></comment> > > ><myclass_data>..contents of t</myclass_data> ... > > > > > > > > > > > Good idea. I'll probably do that. > Another approach would be to preprocess your input files and strip the > added comments using XSLT, perl, or a simple regex program. That way you > don't have to modify the data structures under test. Someone might complain that my original method has 2 inconvenience features a) it requires modification to the serializations b) it includes the (null) comment string place holder in all the archives including the binary one. So another alternative would be to derive from the included xml_?archive classes included in the package and redefine the override for named-value pair so that it inserts/extracts  before or after every tag. This method has the following features: a) doesn't require any kluging up of class serializations b) has the advantage of automatically includes the  for all object instances c) has the disadvantage of automatically includes the  for all object instances d) doesn't add any overhead in other archives. If c) above is intolerable you would have the option of making your own wrapper similar to NVP - (NVT) that you would use in your serializations rather than NVP whenever you wanted a comment place holder. That's really a variation on my first suggestion. Take your pick and good luck Robert Ramey

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question about logging into CVS
by Robert Ramey 05 Jun '04

05 Jun '04

I'm trying to build/update the CVS development tree on my machine and I can't get in. Here is my command line and response. What magic am I missing here? It seemed I had this problem some time ago and it just went away after a time. This time I've tried a few times over the lat 24 hours with always the same result. Robert Ramey cvs -d :pserver:anonymous@cvs.boost.sourceforge.net:/cvsroot/boost login Logging in to :pserver:anonymous@cvs.boost.sourceforge.net:2401:/cvsroot/boost cvs [login aborted]: connect to cvs.boost.sourceforge.net:2401 failed: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.

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Formal Review Tribool
by Thomas Witt 05 Jun '04

05 Jun '04

The review of Douglas Gregor's Tribool library begins now and runs through Saturday, May 29. Here is a short introduction to the library: The 3-state boolean library contains a single class, boost::logic::tribool, along with support functions and operator overloads that implement 3-state boolean logic. The tribool class acts like the built-in bool type, but for 3-state boolean logic. The three states are true, false, and indeterminate, where the first two states are equivalent to those of the C++ bool type and the last state represents an unknown boolean value (that may be true or false, we don't know). When reviewing the library, please remember to include: * What is your evaluation of the design? * What is your evaluation of the implementation? * What is your evaluation of the documentation? * What is your evaluation of the potential usefulness of the library? * Did you try to use the library? With what compiler? Did you have any problems? * How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? * Are you knowledgeable about the problem domain? And finally, every review should answer this question: * Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. The library is available in the Boost files area as tribool-20031026.tgz Thank you, Thomas Witt -- Thomas Witt witt(a)acm.org

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